Supercavitating medical probe and method of use

Abstract

An electrosurgical working end that utilizes supercavitation phenomenon for controlled application of electrosurgical energy to tissue. In one preferred method of the invention, the system utilizes an electrosurgical surface that is rotatable in a liquid substance at very high surface velocities capable of localized lowering of the pressure of the substance below its saturated vapor pressure to cause supercavitation, and contemporaneously applying electrical energy from the electrosurgical surface across the cavity to ablate adjacent tissue. The system creates supercavitation with surface velocities of greater than about 70 m/sec in a liquid substance by means of high speed rotation and optionally ultrasound actuation.

What is claimed is:  
     
       1. An electrosurgical method for applying electrical energy to body structure comprising:
 (a) immersing an electrosurgical surface in a liquid substance, 
 (b) providing a rate of motion in the electrosurgical surface capable of localized lowering of the pressure of the substance below the saturated vapor pressure thereof to create a cavity; and 
 (c) applying the electrical energy from the electrosurgical surface across the cavity in close proximity to mammalian body structure thereby applying the electrical energy to the body structure. 
 
     
     
       2. The electrosurgical method of  claim 1  including providing the rate of motion of at least 70 m/sec. 
     
     
       3. The electrosurgical method of  claim 1  including providing the rate of motion by at least one of rotation of the electrosurgical surface and ultrasonic actuation of the electrosurgical surface. 
     
     
       4. The electrosurgical method of  claim 1  wherein step (c) ablates a portion of the body structure. 
     
     
       5. The electrosurgical method of  claim 4  further comprising translating the electrosurgical surface to apply the electrical energy to a surface portion of the body structure. 
     
     
       6. The electrosurgical method of  claim 4  further comprising penetrating the electrosurgical surface into a tissue of the mammalian body structure to ablate a path in the tissue. 
     
     
       7. The electrosurgical method of  claim 1  wherein the applying of the electrical energy across the cavity is carried out between first and second opposing polarity portions of the electrosurgical surface. 
     
     
       8. The electrosurgical method of  claim 1  wherein the applying of the electrical energy across the cavity is carried out between a first polarity of the electrosurgical surface and a second polarity of a ground pad. 
     
     
       9. An electrosurgical method for applying electrical energy to body structure comprising:
 (a) immersing a working end including a moveable working surface in a liquid substance, 
 (b) providing a rate of motion in the working surface capable of localized lowering of the pressure of the substance below the saturated vapor pressure thereof to create a cavity; and 
 (c) applying the electrical energy across the cavity in close proximity to mammalian body structure thereby applying the electrical energy to said body structure. 
 
     
     
       10. The electrosurgical method of  claim 9  wherein providing the rate of motion in the working surface causes localized increase of the impedance of the substance by a factor of at least one hundred. 
     
     
       11. The electrosurgical method of  claim 9  wherein providing the rate of motion in the working surface causes localized increase of the impedance of the substance by a factor of at least one thousand. 
     
     
       12. The electrosurgical method of  claim 9  wherein the applying of the electrical energy across the cavity is carried by at least one electrode in the working end. 
     
     
       13. The electrosurgical method of  claim 9  wherein the applying of the electrical energy across the cavity is carried by at least one electrode in the working surface.